1. Field of the Invention
This invention relates to a vehicle rear structure provided with a curtain air bag device which spreads out so as to cover sides of a vehicle cabin when the vehicle has a side bump, a rollover or the like, to protect passengers.
2. Description of the Background Art
Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 2004-189099 and United State Unexamined Patent Publication No. 2004-150198, a curtain member or an air bag is fixedly attached along sides of pillars and a roof. Upon collision or the like, the curtain member is inflated with a gas pressure produced by an inflator to thereby spread out the curtain member to cover the sides of a cabin space of the vehicle, specifically, regions from the sides of a roof trim to predetermined lower positions in the front of a rear pillar, and protect an occupant from an impact given when the vehicle collides sideways, rolls over or other accident.
Furthermore, Japanese Unexamined Patent Publication No. 2004-314655 discloses provision of a roof side trim or a roof side inner garnish which is made of a harder material than a roof trim along an upper end of a side window glass or a quarter window glass or the like. A lower part of a roof side rail is covered with the roof side trim. A curtain member is provided along an overlapping zone of an inner side end of the roof side trim and a side end of the roof trim, and is spread out from a boundary between the inner side end of the roof side trim and the side end of the roof trim owing to the fact that a spreading pressure of the curtain member deforms downward them.
In the configuration, as disclosed the former two prior art documents, that the curtain member (air bag) is spread out so as to cover the sides of the cabin space of the vehicle from the outer end of the roof trim to a predetermined lower position in front of the rear pillar, a front lower end of the curtain member is hooked on a front pillar and a rear lower end of the curtain member is hooked on the rear pillar to thereby hold the spread state stably. This offers an advantage in that when the vehicle bumps sideways, rolls over or meets other accident, the curtain member contributes to effectively restraining an occupant or a part of the occupant's body from being moved outward.
However, if the rear pillar trim is not adequately deformed in the process of the curtain member spreading out toward the cabin space of the vehicle from the boundary between the rear end of the roof trim and the front upper end of the rear pillar trim, the rear pillar trim will hinder the curtain member from spreading out. Besides, in cold areas, the rear pillar trim made of a synthetic resin, such as polypropylene has a tendency of reducing the strength as the surrounding temperature decreases, and causes the problem that the spreading curtain member breaks off the front upper end or other portion of the rear pillar trim.
In the configuration, as disclosed in the third prior art document, that the roof side trim is provided to cover the lower part of the roof side rail, it is necessary to deform the boundary between the roof side trim made of a harder material than the roof trim and the rear pillar trim, specifically, the part in which the rear end of the roof side trim and the front upper end of the rear pillar trim overlap each other in order to spread out the curtain member toward the cabin space of the vehicle. This raises the problem that the spreading pressure of the curtain member is likely to damage the rear end of the roof side trim and the front upper end of the rear pillar trim.